guava常用集合交集，差集，并集，补集 *** 作

guava常用集合交集，差集，并集，补集 *** 作

 <!-- https://mvnrepository.com/artifact/com.google.guava/guava -->

        <dependency>

            <groupId>com.google.guava</groupId>

            <artifactId>guava</artifactId>

            <version>21.0</version>

        </dependency>

　<!-- https://mvnrepository.com/artifact/com.google.guava/guava -android结尾兼容jdk1.7 -->
　　　　　<dependency>
   　　　　　　<groupId>com.google.guava</groupId>
    　　　　　　<artifactId>guava</artifactId>
   　　　　　　 <version>22.0-android</version>
　　　　　</dependency>

　　<!-- https://mvnrepository.com/artifact/net.sourceforge.javacsv/javacsv -->
　　　　　　<dependency>
　　　　　　　　<groupId>net.sourceforge.javacsv</groupId>
　　　　　　　　<artifactId>javacsv</artifactId>
　　　　　　　　<version>2.0</version>
　　　　　　</dependency>

引用guava jar文件

import com.csvreader.CsvReader;

import com.google.common.collect.Sets;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import java.io.IOException;

import java.nio.charset.Charset;

import java.util.*;

import static com.google.common.collect.Sets.newHashSet;

/**

 * @Author: SimonHu

 * @Date: 2019/11/12 14:35

 * @Description:

 */

public class BillCompareUtil {

    private static final Logger log = LoggerFactory.getLogger(BillCompareUtil.class);

    public static void main(String[] args) {

        String csvFilePath02 = "C:\\Users\\admin\\Desktop\\app订单0905-02.csv";

        String csvFilePath01 = "C:\\Users\\admin\\Desktop\\app订单0905.csv";

        compare(csvFilePath01, csvFilePath02, 3);

    }

    /**

     * @param path1

     * @param path2

     * @param type  1交集2差集3并集

     * @return java.util.Map

     * @Description:对比文档 运行出错，请注意使用jdk1.8以上进行编译

     * @Author:SimonHu

     * @Date: 2019/11/12 14:44

     */

    public static Map compare(String path1, String path2, int type) {

        ArrayList<String[]> csvList01 = new ArrayList<String[]>();

        ArrayList<String[]> csvList02 = new ArrayList<String[]>();

        try {

            long start = System.currentTimeMillis();

            Set<Map<String, String>> set1 = newHashSet();

            Set<Map<String, String>> set2 = newHashSet();

            //解决中文编码

            CsvReader reader01 = new CsvReader(path1, ',', Charset.forName("GBK"));

            CsvReader reader02 = new CsvReader(path2, ',', Charset.forName("GBK"));

            //reader.readHeaders(); // 跳过表头   如果需要表头的话，不要写这句。



            //逐行读入除表头的数据

            while (reader01.readRecord()) {

                csvList01.add(reader01.getValues());

            }

            //逐行读入除表头的数据

            while (reader02.readRecord()) {

                csvList02.add(reader02.getValues());

            }

            reader01.close();

            reader02.close();

            for (int row = 0; row < csvList01.size(); row++) {

                Map<String, String> map01 = new HashMap();

                String cell0 = csvList01.get(row)[0];

                String cell1 = csvList01.get(row)[1];

                map01.put("订单号", cell0);

                if (cell1.indexOf(".") == -1) {

                    map01.put("金额", cell1);

                } else {

                    String cell2 = cell1.substring(0, cell1.indexOf("."));

                    map01.put("金额", cell2);

                }

                set1.add(map01);

            }

            for (int row = 0; row < csvList02.size(); row++) {

                Map<String, String> map02 = new HashMap();

                String cell0 = csvList02.get(row)[0];

                String cell1 = csvList02.get(row)[1];

                if (cell1.indexOf(".") == -1) {

                    map02.put("订单号", cell0);

                    map02.put("金额", cell1);

                } else {

                    String s01 = cell1.substring(0, cell1.indexOf("."));

                    map02.put("订单号", cell0);

                    map02.put("金额", s01);

                }

                set2.add(map02);

            }

            Map map = new HashMap();

            List<Map> resultList = new LinkedList<>();

            Sets.SetView result = null;

            if (type == 1) {

                result = Sets.intersection(set1, set2);

                System.out.println("交集  intersection:");

                //intersection交集:

            } else if (type == 2) {

                 result = Sets.difference(set1, set2);

                System.out.println("补集  difference:");

                //difference 补集:这里其实是set2相对于set1的补集

            } else if (type == 3) {

                result = Sets.union(set1, set2);

                System.out.println("并集 union:");

            }else if(type == 4){
                //差集
　　　　　　　　　　result = Sets.symmetricDifference(set1,set2)

　　　　　　　 }

            int i=0;

            for (Object u : result) {

                i++;

                Map paramMap = new HashMap();

                System.out.println(u.toString());

                paramMap.put("text","序号:"+i+"------"+u.toString());

                resultList.add(paramMap);

            }

            Map countMap = new HashMap();

            countMap.put("text","总计:"+i+" 条");

            resultList.add(0,countMap);

            map.put("list", resultList);

            long end = System.currentTimeMillis();

            System.out.println((end - start) + "==========ms");

            return map;

        } catch (IOException e) {

            log.error("文件对比失败------", e);

            return null;

        }

    }

}

csv源文件

app订单0905-02.csv

"201992307383892601","490000.00"

"201950907854593602","490000.00"

app订单0905.cdv

"201992307383892601","490001.00"

"201950907854593602","490000.00"

对比结果

交集 intersection:
{orderNo=201950907854593602, trxAmt=490000}
补集 difference:
{orderNo=201992307383892601, trxAmt=490001}
并集 union:
{orderNo=201992307383892601, trxAmt=490001}
{orderNo=201950907854593602, trxAmt=490000}
{orderNo=201992307383892601, trxAmt=490000}

差集 symmetricDifference:
{orderNo=201950907854593602, trxAmt=4901}
{orderNo=201992307383892601, trxAmt=4900}
{orderNo=201950907854593602, trxAmt=4902}

lib引用jar

guava-21.0.jar
javacsv.jar